The Modeling of Regional Climate Over China uses dynamical downscaling techniques for improved understanding of regional climate change. Using China as a test case, we will develop hypotheses about observed climate changes in China. We will make use of observation data to develop and evaluate key processes in Regional Climate Models (RCMs), and apply them with hypothesis testing to improve understanding and modeling of aerosols and land use, and their influence on the hydroclimatic variability and change. In addition, we will further develop the methodology to assess climate change impacts on agriculture and the associated greenhouse gas emissions with and without adaptive and mitigative measures. Through model development and evaluation, we will also advance components related to aerosol-cloud interactions, land-use and landsurface processes, and managed ecosystems in community models. Model development, and evaluation will be conducted to provide an important framework to assess our understanding and modeling of climate change.